Apoptotic cell death is essential for normal development and maintenance of normal tissue size homeostasis in multicellular organisms. There is growing evidence that dysregulation of apoptosis may lead to several human diseases including cancer and degenerative neuronal diseases such as Alzheimer's and Parkinson's diseases.
Several members of the caspase family of proteases (Alnemri, E. S. et al. 1996 Cell 87, 171, which is incorporated herein by reference) have been implicated as key regulators of programmed cell death or apoptosis (Alnemri, E. S. 1997 J. Cell. Biochem. 64, 33-42 and Henkart, P. A. 1996 Immunity 4, 195-201 which are incorporated herein be reference). The pro-apoptotic caspases can be divided into two groups: those with a large prodomain such as ICH-1 (caspase-2), Mch4 (caspase-10), Mch5/MACH/FLICE (caspase-8) and Mch6/ICE-Lap-6 (caspase-9) and those with a small prodomain such as CPP32/YAMA/Apopain (caspase-3), Mch2 (caspase-6) and Mch3/ICE-Lap-3 (caspase-7). Caspases with large prodomains are probably the most upstream caspases. They are recruited by several death-signaling receptors that belong to the TNFR family, through interactions of their prodomain with the receptor-interacting adaptor molecules FADD/Mort1 or CRADD/RAIDD. For example, the prodomains of Mch4 and Mch5 contain two tandem regions that show significant homology with the N-terminal death effector domain (DED) of FADD. Engagement of Fas/TNFR1 results in recruitment of FADD to the receptor complex, which presumably triggers activation of the caspase apoptotic pathway through interaction of its DED with the corresponding motifs in the prodomain of Mch5 and probably Mch4. CRADD presumably functions like FADD by recruiting ICH-1 to the Fas/TNFR1 complex, through interaction of its N-terminal domain with the corresponding motif in the prodomain of ICH-1. Thus, the prodomains of caspases function to physically link the death receptors to the downstream caspase activation pathway.
There is a need to identify proteins that regulate apoptosis. There is a need for isolated FADD-like anti-apoptotic molecules that regulate Fas/TNFR1- or UV-induced apoptosis, and for compositions and methods of producing and isolating FADD-like anti-apoptotic molecules that regulate Fas/TNFR1- or UV-induced apoptosis. There is a need to isolated proteins that are FADD-like anti-apoptotic molecules that regulate Fas/TNFR1- or UV-induced apoptosis. There is a need to isolated nucleic acid molecules that encode FADD-like anti-apoptotic molecules that regulate Fas/TNFR1- or UV-induced apoptosis. There is a need for compounds which inhibit activity of FADD-like anti-apoptotic molecules that regulate Fas/TNFR1- or UV-induced apoptosis. There is a need for kits and methods of identifying such compounds.